Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare non-read-only, non-idempotent, non-destructive, open-world, so the description must add the rest. It usefully discloses that nothing is charged here, that price/shelf/delivery are re-checked, and that delivery_option may silently become next-day or be refused — strong behavioral detail. It does not cover auth/permission needs or whether repeated calls create duplicate orders.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Four tightly packed sentences, front-loaded with the primary action, followed by the return payload, the required next step, and the conditional parameter rule. No sentence is redundant.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, yet the description enumerates the review contents (item, address, exact total, delivery window, quote expiry) and the checkout_token, and names the follow-up call. For a 6-parameter mutation tool with an open-world hint, nothing an agent needs to invoke it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description nonetheless adds real meaning: the variant_id conditional rule and the address semantics reinforce and contextualize what the schema states field-by-field. It stops short of adding format or constraint detail beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Start a real order'), scopes it to one product delivered to the shopper's address, and explicitly differentiates itself from confirm_checkout by naming the two-step flow. An agent can distinguish this from get_product/search_catalog without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit ordering guidance: show the shopper the review, then call confirm_checkout with the token if they accept. It also states the conditional prerequisite for variant_id ('when its variant_required is true'), leaving nothing to inference about when this tool applies.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.